Papaya pulp is very perishable and has a short shelf life. Manually sliced papayas were treated with 0%, 0.25%, 0.5%, and 1% chitosan (non-micronized and micronized) aqueous solutions;placed into plastic trays, and ov...Papaya pulp is very perishable and has a short shelf life. Manually sliced papayas were treated with 0%, 0.25%, 0.5%, and 1% chitosan (non-micronized and micronized) aqueous solutions;placed into plastic trays, and over-wrapped with PVDC film and then stored at 4°C. Color, soluble solid content, water loss, and total plate count of samples were evaluated. Chitosan coating had the ability to maintain the lightness of the sliced papayas. The a* values of the micronized chitosan-coated sliced papayas were significantly lower than those of the-coated. The sliced papayas that had been treated with 1% MC had a higher total soluble solid content and lower b* value after four days of storage. Also, the chitosan coating on the sliced papaya effectively retarded water loss and inhibited the growth of microorganisms. The results reveal that applying a chitosan coating effectively maintained the quality attributes and prolonged the shelf life of the sliced papayas.展开更多
Collagen has been a component of skin care formulations for many years, and over this time, there have been numerous claims of its efficiency. Collagen protein is responsible for firm strong skin, but since collagen f...Collagen has been a component of skin care formulations for many years, and over this time, there have been numerous claims of its efficiency. Collagen protein is responsible for firm strong skin, but since collagen fibers are too large to penetrate the stratum corneum (SC), topical creams containing collagen fibers remain on the skin surface without affecting skin quality. To overcome the poor penetration of collagen fibers, we prepared in the past micronized collagen fibers that were proven to reach the epidermis layer while inserted in a cream. In the present paper, we have performed a clinical study that analyzes the effect of the micronized fibrillar collagen containing cream on skin. Fifty five healthy female volunteers were enrolled and completed the study. The anti-ageing, firming, elasticity and moisturization efficacy of the cream were measured using Profilometer, Cutometer and Corneometer respectively. The results showed a significant improvement in skin hydration firmness and elasticity, a significant reduction in fine lines and wrinkles was also observed.展开更多
We present in this work how to use the dura palm kernel shell powders as loads for the elaboration by extrusion of PVC tubes. The transformation of dura palm kernel shells into micronized shell powder as well as its c...We present in this work how to use the dura palm kernel shell powders as loads for the elaboration by extrusion of PVC tubes. The transformation of dura palm kernel shells into micronized shell powder as well as its characterization was the subject of recent work. We carried out, the formulations by using the industrial scales of precision, the mixtures of the instrants with an industrial machine of mark HENSHLLE N˚2 MAIN 570762, the routine tests by ATG/DSC then by IRTF, the extrusion of the tubes with an extruder twin-screw with 9 rooms of transformation finally the tests of conformity by the observations and the analyses. We obtained for the formulations the dosage of 0%, 4.01%, 12.54%, 23.03%, 32.01%, 38.01%, 51.02% representing the percentage of hull powder in the mixture, the machine mixing gave perfectly homogeneous powders, the routine tests showed that the hull powder keeps all its properties until the end of the shaping whatever the percentage of hulls contained in the PVC, the extrusion gave tubes for each formulation and the conformity tests gave perfectly round tubes of diameter 90 × 82 mm, a coloration going from white grey at 0% to dark black at 51.02% showing the influence of the carbon black and the color of the shell powder according to its proportion. The infrared of the tubes obtained shows for each formulation a variation of the CH<sub>2</sub> and CH bonds and a decrease of the −OH bonds. The thermogravimetric analyses and the differential calorimetric analyses of the tubes of each formulation, show each time that the quantity of shell powders in the mixture influences the PVC tubes obtained. Thus, we obtain a variation of the phase temperatures according to the dosage, giving from 108.72<span style="white-space:normal;">˚</span>C to 76.56<span style="white-space:normal;">˚</span>C for the glass transition temperature and from 494.71<span style="white-space:normal;">˚</span>C to 414.56<span style="white-space:normal;">˚</span>C for the melting temperature, at the DSC and a progressive decrease of the mass following the heat absorption with each time 4 phases instead of 5 for the unloaded PVC tubes at the ATG according to the dosage.展开更多
Background:?Luteal phase support is indicated after Controlled Ovarian Stimulation (COS) using Long Gonadotropin-Releasing Hormone Agonist (GnRHa) protocol in Women undergoing in Vitro Fertilization (IVF)/Intracytopla...Background:?Luteal phase support is indicated after Controlled Ovarian Stimulation (COS) using Long Gonadotropin-Releasing Hormone Agonist (GnRHa) protocol in Women undergoing in Vitro Fertilization (IVF)/Intracytoplasmic Sperm Injection (ICSI). Progesterone is widely used for this indication. Objective: The objective of the current trial is to compare both efficacy and safety of oral dydrogesterone and vaginal micronized progesterone in luteal phase support in women undergoing IVF/ICSI using the long GnRHa protocol. Methods: This open-label randomized controlled study conducted at a private fertility and IVF center in Zagazig, Egypt, during the interval between April 2016 and August 2019. The study included women planned to undergo IVF/ICSI for either male factor infertility, tubal factor infertility, or unexplained infertility. Women with pelvic endometriosis, known reduced ovarian reserve, and women who were known to have poor or high response to ovarian stimulation, as well as women who were stimulated using non-long GnRHa protocol were not included. After embryo transfer, eligible women were randomly allocated into one of the two groups: group I, included women who received oral dydrogesterone 10 mg three times per day;and group II, included women who received vaginal micronized progesterone 400 mg twice per day. The primary outcome was live birth rate. The principal secondary outcome was women satisfaction. Results: Five hundred sixty four women were recruited and randomly allocated into two groups: group I [Oral Dydrogesterone Group] (n = 284), and group II [Vaginal Progesterone Group] (n = 280). Live birth rates [72 (25.4%) vs 69 (24.6%), respectively, RR 1.03, 95% CI (0.77 to 1.37)], ongoing pregnancy rates [79 (27.8%) vs 81 (28.9%), respectively, RR 0.96, 95% CI (0.74 to 1.25)], clinical pregnancy rates [97 (34.2%) vs 95 (33.9%), respectively, RR 1.01, 95% CI (0.80 to 1.27)] and miscarriage rates (per clinical pregnancy) [18 (18.6%) vs 14 (14.7%), respectively, RR 1.26, 95% CI (0.66 to 2.38)] were all comparable in both groups. The rates of vaginal burning [4 (1.4%) vs 32 (11.4%), respectively, RR 0.12, 95% CI (0.04 to 0.34)], vaginal bleeding [9 (3.2%) vs 26 (9.3%), respectively, RR 0.34, 95% CI (0.16 to 0.72)] and overall dissatisfaction [15 (5.3%) vs 68 (24.3%), respectively, RR 0.22, 95% CI (0.13 to 0.37)] were significantly lower among women of group I when compared to women of group II. Conclusion: In conclusion, when compared to vaginal micronized progesterone, oral dydrogesterone seems to be associated with comparable live birth, ongoing pregnancy and clinical pregnancy rates, and significantly lower dissatisfaction and side effects rates, when given as luteal phase support in normal responding women undergoing IVF/ICSI using the long GnRHa protocol.展开更多
The antioxidant activity of chitosan before micronization (BMC, average particle size of 1850 ± 26.3 μm) and after micronization (AMC, average particle size of 1.37 ± 0.2 μm) in grape juice was studied. An...The antioxidant activity of chitosan before micronization (BMC, average particle size of 1850 ± 26.3 μm) and after micronization (AMC, average particle size of 1.37 ± 0.2 μm) in grape juice was studied. Antioxidant activity was determined, including that of DPPH radicals, hydrogen peroxide and superoxide anion radicals, as well as ABTS radicals of BMC or AMC in grape juice. AMC exhibits stronger scavenging activity toward DPPH radicals, superoxide anion radicals and hydrogen peroxide than BMC. At a concentration of 1.0 mg/mL, AMC in grape juice exhibited 90.0%, 97.3% and 88.7% scavenging activities toward DPPH radicals, hydrogen peroxide and superoxide anion radicals, respectively. The TEAC (Trolox Equivalent Antioxidant Capacity) values of AMC (3.94 ± 0.19) greatly exceeded those of BMC (2.21 ± 0.10) in grape juice. The in vitro results in this investigation suggest the possibility that AMC can increase the antioxidant activity in grape juice. However, comprehensive studies must be performed to ascertain the in vivo safety of AMC in experimental animal models.展开更多
In this study,micronized sand is selected as a kind of filler to partially replace cement in cementitious materials. This filler is considered as chemically inert material,which can not react with water or hydration p...In this study,micronized sand is selected as a kind of filler to partially replace cement in cementitious materials. This filler is considered as chemically inert material,which can not react with water or hydration products,but still indirectly influences the hydration in a positive way. In the experimental program,non-evaporable water test was carried out to determine the degree of hydration of cement paste with and without micronized sands. The influence of different finenesses of sand particles,240 m2/kg,400 m2/kg and 1 300 m2/kg,and different curing ages were investigated. The SEM image analysis was used to characterize the morphological changes of microstructure by the presence of the micronized sand during the cement hydration process. Hydration reaction is enhanced by the use of inert micronized sands. The fineness of micronized sands influences the degree of hydration a lot. The fineness factor has been taken into account in the simulation. There is a clear interface area between sand particle and hydration products.展开更多
Marble that exploited for micronized calcite production in Nigde area (South Central Turkey) occur in the Upper Cretaceous Gümü ler, A gedi i, and Kaleboynu Formations of the Nigde Massif. Although there are...Marble that exploited for micronized calcite production in Nigde area (South Central Turkey) occur in the Upper Cretaceous Gümü ler, A gedi i, and Kaleboynu Formations of the Nigde Massif. Although there are a few marble producing quarries in the area, it is long been known that the marbles of this area are generally highly fractured and don’t yield large blocks or suitable slabs meeting the industrial demands. Thus, most of the production is currently carried out mainly as building stone, crushed stone and micronized calcite. Due mainly to high demand, micronized calcite has been becoming very significant export product to the state’s economy. Because the Nigde marbles are coarse grained with high CaCO3 content, high purity and whiteness, they are considered to be the highest quality micronized calcite quarries in the country. Consequently, the area drew many national and international investors resulting in significant increase in the number and extent of micronized calcite plants in the area. In early 1980’s, the city of Nigde had only one or two plants, it is now well over 5 including foreign investors and joint ventures. Annual production is also considerably increased from 20,000-30,000 tones to almost half a million tones and it is still in increasing trend.展开更多
The degradation of mechanical properties of overdischarge battery materials manifests as a significant effect on the energy density,safety,and cycle life of the batteries.However,establishing the correlation between d...The degradation of mechanical properties of overdischarge battery materials manifests as a significant effect on the energy density,safety,and cycle life of the batteries.However,establishing the correlation between depth of overdischarge and mechanical properties is still a significant challenge.Studying the correlation between depth of overdischarge and mechanical properties is of great significance to improving the energy density and the ability to resist abuse of the batteries.In this paper,the mechanical properties of the battery materials during the whole process of overdischarge from discharge to complete failure were studied.The effects of depth of overdischarge on the elastic modulus and hardness of the cathode of the battery,the tensile strength and the thermal shrinkage rate of the separator,and the performance of binder were investigated.The precipitation of Cu dendrites on the separator and cathode after dissolution of anode copper foil is a key factor affecting the performance of battery materials.The Cu dendrites attached to the cathode penetrate the separator,causing irreversible damage to the coating and base film of the separator,which leads to a sharp decline in the tensile strength,thermal shrinkage rate and other properties of the separator.In addition,the Cu dendrites wrapping the cathode active particles reduce the adhesion of the active particles binder.Meanwhile,the active particles are damaged,resulting in a significant decrease in the elastic modulus and hardness of the cathode.展开更多
Ultra-Clean Micronized Coal Water Slurry (UCMCWS ) as a form or coal-based fuel can be used in place of oil in diesel engine, gas turbine and clean combustion. In laboratory UCMCWS has been made from ultra-clean coal ...Ultra-Clean Micronized Coal Water Slurry (UCMCWS ) as a form or coal-based fuel can be used in place of oil in diesel engine, gas turbine and clean combustion. In laboratory UCMCWS has been made from ultra-clean coal with ash less than 0. 8%, with concentration of UCMCWS less than 55%, and with viscosity less than 600 mPa. s. A test rig of atomization with diesel oil nozzle has been made. A preliminary conclusion is that UCMCWS can be atomized as good as diesel oil in the working condition of diesel engine.展开更多
In this experimental study,the impact of Portland cement replacement by ground granulated blast furnace slag(GGBFS)and micronized rubber powder(MRP)on the compressive,flexural,tensile strengths,and rapid chloride migr...In this experimental study,the impact of Portland cement replacement by ground granulated blast furnace slag(GGBFS)and micronized rubber powder(MRP)on the compressive,flexural,tensile strengths,and rapid chloride migration test(RCMT)of concrete were assessed.In this study,samples with different binder content and water to binder ratios,including the MRP with the substitution levels of 0%,2.5%and 5%,and the GGBFS with the substitution ratios of 0%,20%and 40%by weight of Portland cement were made.According to the results,in the samples containing slag and rubber powder in the early ages,on average,a 12.2%decrease in the mechanical characteristics of concrete was observed,nonetheless with raising the age of the samples,the impact of slag on reducing the porosity of concrete lowered the negative impact of rubber powder.Regarding durability characteristics,the RCMT results of the samples were enhanced by using rubber powder because of its insulation impact.Moreover,adding slag into the MRP-included mixtures results in a 23%reduction in the migration rate of the chloride ion averagely.At last,four mathematical statements were derived for the mechanical and durability of concrete containing the MRP and GGBFS utilizing the genetic programming method.展开更多
Iron deficiency anemia is the most frequent nutritional deficiency disorder. Conventionally administered oral iron is associated with gastrointestinal intolerance that affects the outcomes and compliance. Liposomal ir...Iron deficiency anemia is the most frequent nutritional deficiency disorder. Conventionally administered oral iron is associated with gastrointestinal intolerance that affects the outcomes and compliance. Liposomal iron is associated with increased absorption without causing significant adverse effects. In this review, we have discussed the technology of liposomal iron preparation, mechanisms of its absorption and clinical evidence on its utility in iron deficiency states in pregnant and non-pregnant women. Based on the available evidence, we compared liposomal iron to conventional oral iron. Encapsulation of micronized iron in liposomes is associated with lesser exposure to gastric contents, lesser interaction with food contents, no exposure to different digestive juices, targeted delivery of iron and allows lower doses to be administered in lieu of direct absorption without need for protein carriers. The available evidence suggests that liposomal iron significantly increases hemoglobin, ferritin levels in pregnant women as well as in women with iron deficiency.展开更多
目的基于腹腔镜模拟手术训练缺乏有效的训练系统的问题,本文采用双目视觉系统设计了一种腹腔镜模拟手术三维纠偏系统,以达到将原设定切割路径呈现在程序界面,同时实时显示手术刀尖端切割路径,并实现纠正切割路径。方法在Visual Studio 2...目的基于腹腔镜模拟手术训练缺乏有效的训练系统的问题,本文采用双目视觉系统设计了一种腹腔镜模拟手术三维纠偏系统,以达到将原设定切割路径呈现在程序界面,同时实时显示手术刀尖端切割路径,并实现纠正切割路径。方法在Visual Studio 2010软件平台上对Micron Tracker进行二次开发,调用Micron Tracker函数库进行Marker点的识别,采用拉格朗日拟合算法拟合出原定路径,通过逐一调用器械尖端坐标画出器械尖端走过的轨迹。结果使用纠偏系统的A组志愿者和不使用纠偏系统的B组志愿者之间的偏移量比较得出:A组的25次实验整体X轴和Y轴正负平均偏移量均小于B组的偏移量;A、B两组第1次和第5次实验相比,正负平均偏移量均显著减少(P<0.05),且随着受试者操作次数的增加偏移量呈减小的趋势;对A、B两组的正负偏移量进行方差分析,可得因素(纠偏系统)对实验指标(偏移量)有显著影响(F>F-crit)。结论本研究设计的纠偏系统能有效减少培训者在培训过程中的偏移量及培训时间,提高培训效率。展开更多
The booming development of DIW technology present an unprecedented prospect in energetic materials field and has attracted great interest due to its relative simplicity and high flexibility of manufacturing.Herein,a n...The booming development of DIW technology present an unprecedented prospect in energetic materials field and has attracted great interest due to its relative simplicity and high flexibility of manufacturing.Herein,a novel CL-20 based explosive ink formulation have been developed successfully for MEMS initiation systems via DIW technology.We designed PVA/GAP into an oil-in-water(O/W)emulsion,in the way that the aqueous solution of PVA as water phase,the ethyl acetate solution of GAP as oil phase,the combination of Tween 80 and SDS as emulsifier,BPS as a curing agent of GAP.The ideal formulation with good shear-thinning rheology properties and clear gel point was prepared using only 10 wt%emulsion.The dual-cured network formed during the curing process made the printed sample have good mechanical properties.The printed samples had satisfactory molding effect without cracks or fractures,the crystal form of CL-20 not changed and the thermal stability have improved.Deposition of explosive inks via DIW in micro-scale grooves had excellent detonation performances,which critical detonation size was 1×0.045 mm,detonation velocity was 7129 m/s and when the corner reaching 150°can still detonated stably.This study may open new avenues for developing binder systems in explosive ink formulations.展开更多
文摘Papaya pulp is very perishable and has a short shelf life. Manually sliced papayas were treated with 0%, 0.25%, 0.5%, and 1% chitosan (non-micronized and micronized) aqueous solutions;placed into plastic trays, and over-wrapped with PVDC film and then stored at 4°C. Color, soluble solid content, water loss, and total plate count of samples were evaluated. Chitosan coating had the ability to maintain the lightness of the sliced papayas. The a* values of the micronized chitosan-coated sliced papayas were significantly lower than those of the-coated. The sliced papayas that had been treated with 1% MC had a higher total soluble solid content and lower b* value after four days of storage. Also, the chitosan coating on the sliced papaya effectively retarded water loss and inhibited the growth of microorganisms. The results reveal that applying a chitosan coating effectively maintained the quality attributes and prolonged the shelf life of the sliced papayas.
文摘Collagen has been a component of skin care formulations for many years, and over this time, there have been numerous claims of its efficiency. Collagen protein is responsible for firm strong skin, but since collagen fibers are too large to penetrate the stratum corneum (SC), topical creams containing collagen fibers remain on the skin surface without affecting skin quality. To overcome the poor penetration of collagen fibers, we prepared in the past micronized collagen fibers that were proven to reach the epidermis layer while inserted in a cream. In the present paper, we have performed a clinical study that analyzes the effect of the micronized fibrillar collagen containing cream on skin. Fifty five healthy female volunteers were enrolled and completed the study. The anti-ageing, firming, elasticity and moisturization efficacy of the cream were measured using Profilometer, Cutometer and Corneometer respectively. The results showed a significant improvement in skin hydration firmness and elasticity, a significant reduction in fine lines and wrinkles was also observed.
文摘We present in this work how to use the dura palm kernel shell powders as loads for the elaboration by extrusion of PVC tubes. The transformation of dura palm kernel shells into micronized shell powder as well as its characterization was the subject of recent work. We carried out, the formulations by using the industrial scales of precision, the mixtures of the instrants with an industrial machine of mark HENSHLLE N˚2 MAIN 570762, the routine tests by ATG/DSC then by IRTF, the extrusion of the tubes with an extruder twin-screw with 9 rooms of transformation finally the tests of conformity by the observations and the analyses. We obtained for the formulations the dosage of 0%, 4.01%, 12.54%, 23.03%, 32.01%, 38.01%, 51.02% representing the percentage of hull powder in the mixture, the machine mixing gave perfectly homogeneous powders, the routine tests showed that the hull powder keeps all its properties until the end of the shaping whatever the percentage of hulls contained in the PVC, the extrusion gave tubes for each formulation and the conformity tests gave perfectly round tubes of diameter 90 × 82 mm, a coloration going from white grey at 0% to dark black at 51.02% showing the influence of the carbon black and the color of the shell powder according to its proportion. The infrared of the tubes obtained shows for each formulation a variation of the CH<sub>2</sub> and CH bonds and a decrease of the −OH bonds. The thermogravimetric analyses and the differential calorimetric analyses of the tubes of each formulation, show each time that the quantity of shell powders in the mixture influences the PVC tubes obtained. Thus, we obtain a variation of the phase temperatures according to the dosage, giving from 108.72<span style="white-space:normal;">˚</span>C to 76.56<span style="white-space:normal;">˚</span>C for the glass transition temperature and from 494.71<span style="white-space:normal;">˚</span>C to 414.56<span style="white-space:normal;">˚</span>C for the melting temperature, at the DSC and a progressive decrease of the mass following the heat absorption with each time 4 phases instead of 5 for the unloaded PVC tubes at the ATG according to the dosage.
文摘Background:?Luteal phase support is indicated after Controlled Ovarian Stimulation (COS) using Long Gonadotropin-Releasing Hormone Agonist (GnRHa) protocol in Women undergoing in Vitro Fertilization (IVF)/Intracytoplasmic Sperm Injection (ICSI). Progesterone is widely used for this indication. Objective: The objective of the current trial is to compare both efficacy and safety of oral dydrogesterone and vaginal micronized progesterone in luteal phase support in women undergoing IVF/ICSI using the long GnRHa protocol. Methods: This open-label randomized controlled study conducted at a private fertility and IVF center in Zagazig, Egypt, during the interval between April 2016 and August 2019. The study included women planned to undergo IVF/ICSI for either male factor infertility, tubal factor infertility, or unexplained infertility. Women with pelvic endometriosis, known reduced ovarian reserve, and women who were known to have poor or high response to ovarian stimulation, as well as women who were stimulated using non-long GnRHa protocol were not included. After embryo transfer, eligible women were randomly allocated into one of the two groups: group I, included women who received oral dydrogesterone 10 mg three times per day;and group II, included women who received vaginal micronized progesterone 400 mg twice per day. The primary outcome was live birth rate. The principal secondary outcome was women satisfaction. Results: Five hundred sixty four women were recruited and randomly allocated into two groups: group I [Oral Dydrogesterone Group] (n = 284), and group II [Vaginal Progesterone Group] (n = 280). Live birth rates [72 (25.4%) vs 69 (24.6%), respectively, RR 1.03, 95% CI (0.77 to 1.37)], ongoing pregnancy rates [79 (27.8%) vs 81 (28.9%), respectively, RR 0.96, 95% CI (0.74 to 1.25)], clinical pregnancy rates [97 (34.2%) vs 95 (33.9%), respectively, RR 1.01, 95% CI (0.80 to 1.27)] and miscarriage rates (per clinical pregnancy) [18 (18.6%) vs 14 (14.7%), respectively, RR 1.26, 95% CI (0.66 to 2.38)] were all comparable in both groups. The rates of vaginal burning [4 (1.4%) vs 32 (11.4%), respectively, RR 0.12, 95% CI (0.04 to 0.34)], vaginal bleeding [9 (3.2%) vs 26 (9.3%), respectively, RR 0.34, 95% CI (0.16 to 0.72)] and overall dissatisfaction [15 (5.3%) vs 68 (24.3%), respectively, RR 0.22, 95% CI (0.13 to 0.37)] were significantly lower among women of group I when compared to women of group II. Conclusion: In conclusion, when compared to vaginal micronized progesterone, oral dydrogesterone seems to be associated with comparable live birth, ongoing pregnancy and clinical pregnancy rates, and significantly lower dissatisfaction and side effects rates, when given as luteal phase support in normal responding women undergoing IVF/ICSI using the long GnRHa protocol.
文摘The antioxidant activity of chitosan before micronization (BMC, average particle size of 1850 ± 26.3 μm) and after micronization (AMC, average particle size of 1.37 ± 0.2 μm) in grape juice was studied. Antioxidant activity was determined, including that of DPPH radicals, hydrogen peroxide and superoxide anion radicals, as well as ABTS radicals of BMC or AMC in grape juice. AMC exhibits stronger scavenging activity toward DPPH radicals, superoxide anion radicals and hydrogen peroxide than BMC. At a concentration of 1.0 mg/mL, AMC in grape juice exhibited 90.0%, 97.3% and 88.7% scavenging activities toward DPPH radicals, hydrogen peroxide and superoxide anion radicals, respectively. The TEAC (Trolox Equivalent Antioxidant Capacity) values of AMC (3.94 ± 0.19) greatly exceeded those of BMC (2.21 ± 0.10) in grape juice. The in vitro results in this investigation suggest the possibility that AMC can increase the antioxidant activity in grape juice. However, comprehensive studies must be performed to ascertain the in vivo safety of AMC in experimental animal models.
文摘In this study,micronized sand is selected as a kind of filler to partially replace cement in cementitious materials. This filler is considered as chemically inert material,which can not react with water or hydration products,but still indirectly influences the hydration in a positive way. In the experimental program,non-evaporable water test was carried out to determine the degree of hydration of cement paste with and without micronized sands. The influence of different finenesses of sand particles,240 m2/kg,400 m2/kg and 1 300 m2/kg,and different curing ages were investigated. The SEM image analysis was used to characterize the morphological changes of microstructure by the presence of the micronized sand during the cement hydration process. Hydration reaction is enhanced by the use of inert micronized sands. The fineness of micronized sands influences the degree of hydration a lot. The fineness factor has been taken into account in the simulation. There is a clear interface area between sand particle and hydration products.
文摘Marble that exploited for micronized calcite production in Nigde area (South Central Turkey) occur in the Upper Cretaceous Gümü ler, A gedi i, and Kaleboynu Formations of the Nigde Massif. Although there are a few marble producing quarries in the area, it is long been known that the marbles of this area are generally highly fractured and don’t yield large blocks or suitable slabs meeting the industrial demands. Thus, most of the production is currently carried out mainly as building stone, crushed stone and micronized calcite. Due mainly to high demand, micronized calcite has been becoming very significant export product to the state’s economy. Because the Nigde marbles are coarse grained with high CaCO3 content, high purity and whiteness, they are considered to be the highest quality micronized calcite quarries in the country. Consequently, the area drew many national and international investors resulting in significant increase in the number and extent of micronized calcite plants in the area. In early 1980’s, the city of Nigde had only one or two plants, it is now well over 5 including foreign investors and joint ventures. Annual production is also considerably increased from 20,000-30,000 tones to almost half a million tones and it is still in increasing trend.
基金supported by the National Natural Science Foundation of China(92266206,52227810)the Jilin Province Science and Technology Development Plan(YDZJ202101ZYTS129)the Fundamental Research Funds for the Central Universities(2022-JCXK-11)。
文摘The degradation of mechanical properties of overdischarge battery materials manifests as a significant effect on the energy density,safety,and cycle life of the batteries.However,establishing the correlation between depth of overdischarge and mechanical properties is still a significant challenge.Studying the correlation between depth of overdischarge and mechanical properties is of great significance to improving the energy density and the ability to resist abuse of the batteries.In this paper,the mechanical properties of the battery materials during the whole process of overdischarge from discharge to complete failure were studied.The effects of depth of overdischarge on the elastic modulus and hardness of the cathode of the battery,the tensile strength and the thermal shrinkage rate of the separator,and the performance of binder were investigated.The precipitation of Cu dendrites on the separator and cathode after dissolution of anode copper foil is a key factor affecting the performance of battery materials.The Cu dendrites attached to the cathode penetrate the separator,causing irreversible damage to the coating and base film of the separator,which leads to a sharp decline in the tensile strength,thermal shrinkage rate and other properties of the separator.In addition,the Cu dendrites wrapping the cathode active particles reduce the adhesion of the active particles binder.Meanwhile,the active particles are damaged,resulting in a significant decrease in the elastic modulus and hardness of the cathode.
文摘Ultra-Clean Micronized Coal Water Slurry (UCMCWS ) as a form or coal-based fuel can be used in place of oil in diesel engine, gas turbine and clean combustion. In laboratory UCMCWS has been made from ultra-clean coal with ash less than 0. 8%, with concentration of UCMCWS less than 55%, and with viscosity less than 600 mPa. s. A test rig of atomization with diesel oil nozzle has been made. A preliminary conclusion is that UCMCWS can be atomized as good as diesel oil in the working condition of diesel engine.
文摘In this experimental study,the impact of Portland cement replacement by ground granulated blast furnace slag(GGBFS)and micronized rubber powder(MRP)on the compressive,flexural,tensile strengths,and rapid chloride migration test(RCMT)of concrete were assessed.In this study,samples with different binder content and water to binder ratios,including the MRP with the substitution levels of 0%,2.5%and 5%,and the GGBFS with the substitution ratios of 0%,20%and 40%by weight of Portland cement were made.According to the results,in the samples containing slag and rubber powder in the early ages,on average,a 12.2%decrease in the mechanical characteristics of concrete was observed,nonetheless with raising the age of the samples,the impact of slag on reducing the porosity of concrete lowered the negative impact of rubber powder.Regarding durability characteristics,the RCMT results of the samples were enhanced by using rubber powder because of its insulation impact.Moreover,adding slag into the MRP-included mixtures results in a 23%reduction in the migration rate of the chloride ion averagely.At last,four mathematical statements were derived for the mechanical and durability of concrete containing the MRP and GGBFS utilizing the genetic programming method.
文摘Iron deficiency anemia is the most frequent nutritional deficiency disorder. Conventionally administered oral iron is associated with gastrointestinal intolerance that affects the outcomes and compliance. Liposomal iron is associated with increased absorption without causing significant adverse effects. In this review, we have discussed the technology of liposomal iron preparation, mechanisms of its absorption and clinical evidence on its utility in iron deficiency states in pregnant and non-pregnant women. Based on the available evidence, we compared liposomal iron to conventional oral iron. Encapsulation of micronized iron in liposomes is associated with lesser exposure to gastric contents, lesser interaction with food contents, no exposure to different digestive juices, targeted delivery of iron and allows lower doses to be administered in lieu of direct absorption without need for protein carriers. The available evidence suggests that liposomal iron significantly increases hemoglobin, ferritin levels in pregnant women as well as in women with iron deficiency.
文摘目的基于腹腔镜模拟手术训练缺乏有效的训练系统的问题,本文采用双目视觉系统设计了一种腹腔镜模拟手术三维纠偏系统,以达到将原设定切割路径呈现在程序界面,同时实时显示手术刀尖端切割路径,并实现纠正切割路径。方法在Visual Studio 2010软件平台上对Micron Tracker进行二次开发,调用Micron Tracker函数库进行Marker点的识别,采用拉格朗日拟合算法拟合出原定路径,通过逐一调用器械尖端坐标画出器械尖端走过的轨迹。结果使用纠偏系统的A组志愿者和不使用纠偏系统的B组志愿者之间的偏移量比较得出:A组的25次实验整体X轴和Y轴正负平均偏移量均小于B组的偏移量;A、B两组第1次和第5次实验相比,正负平均偏移量均显著减少(P<0.05),且随着受试者操作次数的增加偏移量呈减小的趋势;对A、B两组的正负偏移量进行方差分析,可得因素(纠偏系统)对实验指标(偏移量)有显著影响(F>F-crit)。结论本研究设计的纠偏系统能有效减少培训者在培训过程中的偏移量及培训时间,提高培训效率。
基金This work was supported by the Graduate Education Innovation Project of Shanxi Province(2020SY401)No.55 Research Institute of China North Industries Group Corporation Open Innovation Fund(WDZC2020JJ017).
文摘The booming development of DIW technology present an unprecedented prospect in energetic materials field and has attracted great interest due to its relative simplicity and high flexibility of manufacturing.Herein,a novel CL-20 based explosive ink formulation have been developed successfully for MEMS initiation systems via DIW technology.We designed PVA/GAP into an oil-in-water(O/W)emulsion,in the way that the aqueous solution of PVA as water phase,the ethyl acetate solution of GAP as oil phase,the combination of Tween 80 and SDS as emulsifier,BPS as a curing agent of GAP.The ideal formulation with good shear-thinning rheology properties and clear gel point was prepared using only 10 wt%emulsion.The dual-cured network formed during the curing process made the printed sample have good mechanical properties.The printed samples had satisfactory molding effect without cracks or fractures,the crystal form of CL-20 not changed and the thermal stability have improved.Deposition of explosive inks via DIW in micro-scale grooves had excellent detonation performances,which critical detonation size was 1×0.045 mm,detonation velocity was 7129 m/s and when the corner reaching 150°can still detonated stably.This study may open new avenues for developing binder systems in explosive ink formulations.
